Several methods are known for manufacturing waterproof and vapor-permeable shoes, in which the shoe essentially comprises an upper, a multilayer lining which is arranged inside the upper and is provided with a vapor-permeable and waterproof membrane which, in use, is interposed between the foot and the upper, and a sole glued to the upper. In particular, the vapor-permeable and waterproof membrane called “Gore-tex” is known, consisting of an extremely thin film of TEFLON® E-PTFE (polytetrafluoroethylene) coupled to supporting/protective layers.
One of the aforesaid methods is described in international Patent Application WO2008/119683 and essentially involves preparing an open, shaped upper, i.e. so as to be able to be arranged and developed on one plane, arranging a punctiform adhesive between the upper and the membrane, arranging a waterproof and vapor-permeable membrane on the inner part of the upper, preparing shapes having two flat and parallel lateral sides associated with the model of the shoe to be manufactured, securing the membrane to the upper previously arranged about the shape with the outer surface in contact therewith, folding back the assembly comprising membrane and upper and couple it to an insole, and finally coupling the sole to the insole and to the upper.
Although the above-described method on the one hand has decreased the operating complexity of the preceding manufacturing methods, thus reducing costs and times and guaranteeing at the same time both satisfactory waterproofness and vapor-permeableness of the shoe and the elimination of the formation of water stagnation between upper and membrane, on the other hand it does not completely meet the current need to further simplify the procedure for manufacturing the shoe so as to contain/reduce the manufacturing prices thereof.
Indeed, there is a need to manufacture a vapor-permeable and waterproof shoe which in particular prevents water from penetrating and stagnating between upper and membrane, without shaking the current “traditional” lines/procedures for manufacturing shoes, that is, without requiring the use of additional machines and/or components with respect to those already generally used/present in traditional shoe manufacturing companies.
In particular, the above-described method involves using specific flat shapes for each shoe model to be manufactured and modifying/replacing the same on the basis of the shoe models. Obviously this requirement/restriction does not satisfy the above-mentioned need because it affects the complexity and therefore manufacturing times of the waterproof and vapor-permeable shoe in a considerable manner, thus leading to an increase in costs.
Patent Application EP 2 238 859 A1 describes a method for manufacturing a waterproof and vapor-permeable shoe in which it is envisaged to: secure a first gasket of vapor-permeable material having a holed vapor-permeable portion to a vapor-permeable assembly insole, connect the assembly margins of an assembly provided with an upper and a lining, provided with a waterproof and vapor-permeable membrane, to the first gasket according to the construction known as AGO lasting such as to obtain the assembly of the shoe, assemble a second gasket straddling the assembly margins of the first gasket so as to seal them and finally, assemble the sole to the assembly so as to ensure that the material of the sole adheres to the second gasket. The method described in Patent Application EP 2 238 859 A1 has the drawback of requiring the application of two gaskets with obvious consequences in terms of increased manufacturing times and costs of the shoe. The use of the second gasket is indeed essential because folds which are not completely sealed by the first gasket are formed on the upper during the assembly step, at the toe and/or heel. To this end, Patent EP 2 238 859 teaches to arrange a second gasket straddling the assembly margins of the first gasket so as to prevent the infiltration of water through the folds in the upper.
Patent Application WO2008/118772 describes a method for manufacturing a waterproof and vapor-permeable shoe in which it is envisaged to sew the border of the upper to a sealing band and to couple the ribbon-shaped sealing band and the edge of a functional element of the upper to a peripheral margin of the insole. The employment of the sealing band is complex, inconvenient, lengthens manufacturing times and increases costs for executing the method.
The Applicant has carried out in-depth research to identify a solution that specifically allows achieving the aim of providing a method for manufacturing a vapor-permeable and waterproof shoe, that is simple and affordable.